Halogenated alkyl carbonates and process for producing the same



Patented Dec. 21, 1943 UNlTE STATES HALOGENA'IED ALKYL CARBONATES AND I I PROCESS FOR PRODUCING THE SAME Bruno H. Wojcik, Niagara Falls, N. Y., assignor to Hooker Electrochemical Company, Niagara v Falls, N. Y., a corporation of New York -No Drawing. Application MayjZl, 1941, i Serial No. 394,495 I 4; Claims. I (01. 260-4li3) It is known that phosgene will react with alcohols to produce chlorcarbonates orcarbonates,

the latter being of course esters of carbonic acid. If the reagents are in equimolecular proportions}.

one chlorine atom of the phosgene will split off with the hydrogen of theOH group, producing a chlorcarbonate, as follows:

RH+c0c12 Ro coc1+ c1 (1) It is also known that if the reagents are in the proportion of two molecules of they alcohol to one of the phosgene, both chlorine atoms will split 01? with the hydrogen of two alcohol molecules, pro--v ducing a carbonate, as follows:

: 2ROH+COCl-2 ROCO0R+2HCl It is likewise known that theproduct of reaction (1) may be reacted with an equimolecular quantity of a different alcohol, producing what I call a mixed carbonate, as follows:

resins; but the compatibility of the aryl, and

long chain dialkyl, mixed alkyl and aryl-alkyl weight of chlorine, The chlorinated alkyl chlorcarbonates, like their unchlorinated originals, are

unstable, reactive, -.volatile and lachrymatoryij The chlorinated alkyl' carbonates are fluids of good stability, colorless ,or nearly so, and of a consistency ranging from that of glycerine to that of chilled honey. The short chain products have-the pleasant odor characteristic of estersl The'long chain prcducts are substantially odorless. I

For present purposes I am therefore concerned I with the chlorinated derivatives of'alkyl carbonproducts with most resins is unsatisfactory and the corresponding short chain products are too volatile to withstand the temperatures involved in working them into the resins. This is also generally true of all the chlorcarbonates. These latter compounds, besides being volatile, are unstable, and quit reactive. They are'apparently related to the class of compounds known as lachrymators.

Some of the diaryl carbonates, such as diphenyl carbonate, have been chlorinated to replace hydrogen in their carbon rings, but these compounds take up chlorine quite reluctantly. Except when they are mixtures of isomers, as in the case of dicresyl carbonate, for example, the chlorinated products are generally solids at ordinary-temperatures. In any case, their compatibility with resins is unsatisfactory. These compounds also have an extremely pungent and unpleasant odor. I ,l

I have now discovered that the dialkyl and mixed alkyl chlorcarbonat es and carbonates may be chlorinated very readily,,and that some of them will take up as much as 70 per cent of their pose.

ates only, and by this term I intend to designate not only the di alkyl' carbonates of reaction (2) i but also the mixed allzyl carbonates that may be ,produced byreaction (3), from monohydroxy or polyhydroxy alkyl alcohols.

I To the best of my knowledge and beliefithese products are new'compositions of matter.

Mynew chlorinated dialkyl and mixed alkyl. carbonates, as distinguished from the correspending chlorcarbonates such as may be produced by reaction 1). have good heat and light stabilityy comparing favorably in this respect with the chlorinated parafiins.

Myproducts are non-inflammable and flame resistant, and this is especially true of those of relatively high chlorine content. Thus, the products containing 45 per cent chlorine or higher cannot be made to burn even when a flame is played directly upon them. Some of the products containing less than 45 per cent chlorine can be made to char or burn by playin a flame upon them, but cease to burn instantly when the flame is removed. f My products are water insoluble, and since they resist oxidation some of them are useful as impregnating compositions for fibrous materials, such as fabrics. for water proofing, Weather proofing, fire proofing, etc, I

My products also have excellent dielectric properties'and. some of them are useful for impregnating fibrous electrical insulation.

Some of my products are suitable for coating air filters to trap dust. Their relative freed-3m from odor make them very suitable for this pur- This is especially true .of those of long chain.

My products are miscible with mineral lubricating oils up to very substantial proportions, such as twenty or thirty per cent or more, depending on the chlorine content. This is especially true ofv those of short chain. Since they contain chlorine, which is known to increase the film strength or load carrying capacity of such their lubricity, and can be made neutral or nearly so, my products are valuable addition agents for such oils.

Many of my products are also compatible with a large number of natural and synthetic resins, in proportions sufiicient to plasticize them, or, in other words, to modify their physical characteristics so as to convert the brittle resins to tough, strong solids or to flexible or elastic materials oi the type known as elastomers, all of which are useful for many purposes.

Among the short chain members of my group of products may be mentioned chlorinated diethyl carbonate and among the long chain members chlorinated dioctadecyl carbonate. The length of the-chain is limited principally by the difiiculty of forming the corresponding alcohols from long chain hydrocarbons.

Obviously these chlorinated dialkyl and mixed positions of special properties.

My chlorinated mixed alkyl carbonates, such as may be produced from two difierent alkyl alcohols in accordance with reaction (3), form useful groups 01 compounds with special properties that are susceptible of wide variation. Thus, if we start with a number .of different alcohols and hook them up in all possible combinations we shall have a much greater number of products than the original number of alcohols. By mixing these diverse products, mixtures having greater fluidity than that of the separate components may be secured. Such mixtures may be superior for special purposes, and this is especially true when these materials are to be used as plasticizers.

The degree of chlorination of course affects the properties of these products and this can be varled within wide limits, up to a chlorine content of 50 or '70 per cent. The chlorine undoubtedly increases the compatibiity "of these carbonates with resins and especially with those containin chlorine, such as the polyvinyl chlorides, at least up to a certain point.

Example I Anefifort was made to-produce dimethyl carbonate by reaction of methyl alcohol with phosgene, but the reaction was found to be negligible. F

Example II An attempt was made to chlorinate diethyl carbonate at 105 C., but when the chlorine content had reached 55 per cent solids formed and sublimed into the condenser. By keeping the temperature range down to between 60 and 70 "C. thechlorine content was carried to 69 per cent, corresponding to an average of 7.6 atoms of chlorine per molecule, as compared with a possible maximum of ten chlorine atoms per molecule. Upon cooling, white crystals developed and settled out, leaving an oily, colorless, volatile, supernatant liquid.

Example III v alkyl carbonates may be blended to produce comspecific electrical resistance of 18,500,000 ohms.

Heated to 1&0 C. for 16 hours, this material gave 0112.2 mg. of HCl per 1 gram of sample. This indicates excellent heat stability.

Erample IV Dibutyl carbonate was chlorinated as before until the chlorine content had reached 29.3 per cent, corresponding to dichlordibutyl carbonate. The product was substantially colorless, but still somewhat volatile.

Example VI Dibutyl carbonate was chlorinated as before until the chlorine content had reached 38.4 per cent, corresponding to trichlordibutyl carbonate. The product was an oily, substantially colorless liquid, having a slight but pleasant odor.

Example VII Di-n-amyl carbonate was chlorinated, starting at C. and finishing at 115 C., when the chlorine content was found to be 55 per cent. The product was air blown at C. It was a syrupy, substantially colorless, odorless fluid, of the consistency of fresh, honey at ordinary temperatures.

Example VIII Di-isoamyl carbonate was chlorinated as in the preceding example to a chlorine content of 52.8 per cent. The product was a thick, viscous, substantially colorless and odorless fluid, very similar to that of Example VII.

Example IX Di-z-ethyl hexyl (dioctyl) carbonate was heated to C. and chlorinated at 100 to C. until it contained about 39 .per cent chlorine, at which point the temperature began to drop, showing that the chlorine was being taken up less readily. The chlorination was discontinued and the product was air blown for about 1 /2 hours at 50 to 60 C. The product was a syrupy, slightly tinted, odorless and tasteless fluid. Its specific resistance, 1. e., the resistance to flow of current between two electrodes 1 cm. square immersed in the material 1 cm. apart, was 3,192,000 ohms. Heated to C., it evolved only 1.1 mg. of H01 per 1 gram of sample in 16 hours. This .15 considered evidence of excellent stability.

Example X Dilauryl (didodecyl) carbonate was heated to 105 C. and chlorinated. When the chlorine content had reached 30 per cent of its weight of chlorine the reaction seemed to slow up and the only, and are not to be taken as a com lete list of my new chlorinated esters of carbonic acid. Obviously many others will suggest themselves to persons skilled in the art. The following examples are given for comparison of the aryl with the alkyl products:

Example XII An attempt was made to chlorinate diphenyl carbonate at 100 to 110 C. It would not take up the chlorine. The temperature was increased to 140 C. and then to 170 C. A catalyst was added. In this way chlorine was introduced to a content of 27 per cent. The product however, was a reddish brown solid and had a very unpleasant odor of phenol.

From the foregoing examples the following conclusions may be drawn:

(a) Under the conditions of the experiment, the limit of capacity of the long chain alkyl carbonates to take up chlorine, expressed as a percentage of their weight, is lower than that of the short chain' alkyl carbonates.

(b) Short chain alkyl carbonates chlorinated to the limit of their capacity to take up chlorine are more viscous than long chain alkyl carbonates chlorinated to like degree.

Chlorinated short chain alkyl carbonates are more volatile than chlorinated long chain alkyl carbonates containing the same proportion of chlorine and have more odor, but the odor is always pleasant.

(d) Thelong chain alkyl carbonates and the aryl carbonates require a higher temperature for chlorination and when chlorinated show more color than the short chain alkyl carbonates chlorinated to like degree.

(e) The chlorinated alkyl carbonate having 4 and 5 carbon atoms in their alkyl groups, including those of very high chlorine content, are substantially colorless and those having 40 to 70 per cent chlorine are likewise substantially odorless. v

(f) The chlorinated alkyl carbonates of 4 and w 5 carbon atoms when chlorinated to the limits of their capacity readily to take up chlorine are more viscous than any of the products that can be made from alkyl carbonates of a less or greater number of carbon atoms or from any aryl carbonates.

(9) Under the conditions of the experiment,

oil and have a very disagreeable odor, precluding their use for many purposes, including all of applicants purposes mentioned above.

(it). The diaryl carbonates that are substantially chemical individuals chlorinate with great difficulty to solid, highly colored products, of very unpleasant odor and limited compatibility with mineral oils and resins, and on these accounts useless for most of applicants purposes.

' I claim as my invention:

1. As new compositions of matter, the mixtures of substitution products resulting from the reaction of chlorine with organic carbonates of the general formulae RO-COOR and RO-CO-OR',

in which R and R represent alkyl radicals of four to twelve carbon atoms, the compositions, after removal of the by-product hydrogen chloride, containing substantially 16.5 to 68 per cent chlorine and being slightly tinted to substantially colorless, sweetish smelling to substantially odorless, and non-inflammable to flame-resistant, and ranging from oily liquids having about the volatility of 'kerosene to non-volatile fluids having about the viscosity of chilled honey, gen erally miscible with mineral oils and compatible with natural and synthetic resins.

2. As new compositions of matter, the mixtures of substitution products resulting from the reaction of chlorine with dibutyl carbonates, the compositions, after removal of the by-product hydrogen chloride, containing substantially 16.5 to 68 per cent chlorine and being slightly tinted to substantially colorless, sweetish smelling to substantially odorless, and non-inflammable to flame-resistant, and ranging from oily liquids having about the volatility of kerosene to nonvolatile viscous fluids, generally miscible with mineral oils and compatible with natural and synthetic resins.

3. As new compositions of matter, the mixtures of substitution products resulting from the reaction of chlorine with diamyl carbonates, the compositions, after removal of the by-product hydrogen chloride, containing substantially 53 to 55 per cent chlorine and being slightly tinted to substantially colorless, substantially odorless, flame-resistant, viscous, syrupy fluids, generally miscible with mineral oils and compatible with natural and synthetic resins.

4. As new compositions of matter, the mixtures of substitution products resulting from the reaction of chlorine with dioctyl carbonate, the compositions, after removal of the by-product hydrogen chloride, containing substantially 39 per cent. chlorine and being slightly tinted to substantially colorless, substantially odorless and tasteless, syrupy, flame-resistant fluids, of good stability and high dielectric properties, generally miscibles with mineral oils and com-v patible with natural and synthetic resins.

BRUNO H. WOJCIK. 

